US4451862A - Magnetic head mounting mechanism for automatic azimuth control - Google Patents

Magnetic head mounting mechanism for automatic azimuth control Download PDF

Info

Publication number
US4451862A
US4451862A US06/454,212 US45421282A US4451862A US 4451862 A US4451862 A US 4451862A US 45421282 A US45421282 A US 45421282A US 4451862 A US4451862 A US 4451862A
Authority
US
United States
Prior art keywords
head
magnetic
magnetic head
deflection element
support
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06/454,212
Other languages
English (en)
Inventor
Albert M. A. Rijckaert
Henricus M. Ruyten
Johannes F. Hoefnagels
Johannes J. M. Schoenmakers
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Philips Corp
Original Assignee
US Philips Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US4451862A publication Critical patent/US4451862A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/56—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head support for the purpose of adjusting the position of the head relative to the record carrier, e.g. manual adjustment for azimuth correction or track centering
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/10—Structure or manufacture of housings or shields for heads
    • G11B5/105—Mounting of head within housing or assembling of head and housing

Definitions

  • the invention relates to an apparatus for recording and/or reproducing information on a magnetic tape, provided with a frame portion, on which is arranged at least one head support which carries a magnetic head and a positioning device, which prsitioning device comprises an electromechanical deflection element which is rigidly connected to the head support and which comprises mounting or fixing portions adjacent two opposite edges of the element, including a fixing portion which is connected to the magnetic head and the magnetic head being pivotable relative to the head support by the deflection element in order to adjust the azimuth-angle position of the magnetic head.
  • azimuth-angle position of the magnetic head For the reproduction of information recorded in tracks on a magnetic tape it is of great importance that the azimuth-angle position of the magnetic head relative to the axis of the relevant information tracks to be reproduced is correctly aligned during the reproduction process.
  • a deviating azimuth-angle position of the magnetic head, which deviation is the so-called "azimuth error" results in a less satisfactory reproduction of the higher frequencies of the information signal.
  • an azimuth error of only a few minutes of arc may result in a reduction of the high-frequency reproduction of an audio signal by a few kHz.
  • azimuth angles are eliminated by pivoting the magnetic head by means of a positioning device.
  • the positioning device comprises two piezo-electric deflection elements, situated one to each side of the magnetic head, which elements are each rigidly connected to the head support at their centers. The top and bottom ends of each deflection element are connected to the magnetic head through elastic hinges. Because of this fairly intricate construction of the positioning device, the maximum deflection of the deflection elements and thus the maximum attainable pivoting range of the magnetic head and the maximum azimuth error that can be corrected are comparatively small. When the magnetic head is pivoted mutual positioning deviations may occur between each deflection element and the magnetic head owing to the hinged connections, so that the azimuth correction is performed with a delay or incompletely.
  • the positioning device comprises only one deflection element, of which deflection element only a first fixing portion is connected to the magnetic head and a second fixing portion is connected to the head support, which connections are both rigid.
  • the electromechanical deflection element of an apparatus in accordance with the invention can perform a comparatively large deflection and can thus pivot the magnetic head through such an angle that even considerable azimuth errors can be corrected.
  • the magnetic head Owing to the rigid connection between the first fixing portion of the deflection element and the magnetic head the magnetic head accurately follows the movement of the first fixing portion, so that an azimuth error is corrected effectively.
  • the apparatus can reproduce information signals recorded on a magnetic tape without loss of high frequencies under substantially all conditions, regardless of the azimuth angle position of the magnetic head which has been used for recording.
  • the positioning device together with the magnetic head can form a compact unit, so that the invention is particularly suitable for use in equipment where only a small space is available around the magnetic head.
  • an embodiment of an apparatus in accordance with the invention is characterized in that the positioning device and the magnetic head are enclosed by a shield, which is at least partly constituted by the head support.
  • this embodiment is further characterized in that the deflection element is situated in a space which is bounded by a wall of the magnetic head and of the shield respectively, and in a rest position the piezo-electric element extends substantially parallel to said walls.
  • the first and second fixing portions of the deflection element are rigidly mounted on a first holder and a second holder respectively of the positioning device, which holders are secured to a wall of the magnetic head and a wall of the shield respectively.
  • the second holder and the wall of the shield are provided with mutually cooperating adjusting means which enable the position of the second holder relative to the wall of the shield to be adjusted. This provides the possibility of accurately positioning the magnetic head together with the positioning device relative to the shielding cover.
  • the positioning device also comprises at least one elastic hinge, whose hinge axis coincides with the axis about which the magnetic head is pivotable by means of the deflection element.
  • the operation of the deflection element cannot be impaired by forces exerted on the magnetic head.
  • a suitable construction of this embodiment is further characterized in that there are provided two elastic hinges, which are situated on opposite sides of the deflection element and which are each connected to the two holders.
  • the head support is supported on the frame portion by means of at least one knife-edge bearing so as to be capable of pivotal movement, which pivotal movement also enables the azimuth-angle position of the magnetic head to be adjusted.
  • a further embodiment of an apparatus in accordance with the invention is characterized in that the deflection element is situated substantially completely within the magnetic head, symmetrically relative to the air gaps, in a space formed between the magnetic cores.
  • the apparatus is provided with both a magnetic recording head for recording information and a magnetic reproducing head for reprodicing information, only the magnetic reproducing head being connected to the head support by means of the positioning device.
  • the position of the magnetic recording head is not influenced by the azimuth correction of the magnetic reproducing head.
  • FIG. 1 is a plan view of a part of an apparatus in accordance with the invention.
  • FIG. 2 is a partial cross-section and partial elevation on an enlarged scale of a part of the apparatus of FIG. 1.
  • FIG. 3 is a plan view in accordance with the arrow III in FIG. 2.
  • FIG. 4 is an elevation in accordance with the arrow IV in FIG. 3.
  • FIG. 5 schematically illustrates the operation of a deflection element in an apparatus in accordance with the invention.
  • FIG. 6 is a partial cross-section and partial elevation on an enlarged scale of a part of a second embodiment of an apparatus in accordance with the invention.
  • FIG. 7 is a partial cross-section and partial elevation on an enlarged scale of a part of a third embodiment of an apparatus in accordance with the invention.
  • FIG. 8 is a partial cross-section and partial elevation on an enlarged scale of a part of a fourth embodiment of an apparatus in accordance with the invention.
  • FIG. 9 shows a cross-section taken on the lines IX--IX in FIG. 8.
  • FIG. 10 is a plan view of a part of a fifth embodiment of an apparatus in accordance with the invention.
  • FIG. 1 shows the relevant parts of an apparatus 1 which enables audio information to be recorded on and/or reproduced from a magnetic tape 2 contained in a substantially rectangular cassette 3.
  • the tape is wound on two winding hubs and is passed between the winding hubs along a long side of the cassette.
  • the apparatus is provided with a frame portion 4 which is connected to the remaining part of the apparatus in such a way as to be movable relative to the cassette 3.
  • the frame portion 4 serves as a head mounting plate for two magnetic heads, such as a magnetic erase head 5 and a combined magnetic recording/reproducing head 6.
  • the cassette has a side wall in which a number of openings are formed which enable the magnetic heads 5 and 6 to be brought into operative contact with the magnetic tape 2 by moving the frame portion 4 in the direction of the cassette, and which enable the magnetic head to be pressed againt a capstan 8 by means of a pressure roller 7.
  • the which capstan is coupled to a drive mechanism, not shown, of the apparatus.
  • the magnetic head 6 is arranged above the frame portion 4 in the manner shown in FIGS. 2 to 4.
  • the frame portion 4 comprises two mutually spaced fixed supports 9 and 10, each of which has a slot in its top surface, facing the magnetic head 6.
  • End portions of tabs 11 and 12 are lightly pressed against the slot bottoms, and function as knife-edge bearings about which the magnetic head is pivotable relative to the frame portion 4.
  • the common pivotal axis of these knife-edge bearings extends at least substantially at right angles to the long side wall of the cassette 3.
  • the tabs 11 and 12 form part of a head support 13, which has a vertical supporting portion 14 as well as a base portion 15 which extends substantially at right angles to the supporting portion. As is shown in FIGS.
  • the tabs 11 and 12 are close to the supporting portion 14.
  • the tabs 11 and 12 are shaped so that the end portions of the tabs, with respect to the direction of tape transport during reproduction or recording, indicated by the arrow A in the FIGS. 2 and 3, are situated in a plane lying substantially halfway between substantially parallel opposed walls 16 and 17 of the supporting portion 14 and the magnetic head 6 respectively.
  • the base portion 15 is provided with a projection 18 in which an opening is formed through which an adjusting screw 19 passes. The far end of the screw 19 engages a threaded hole 20 in the frame portion 4.
  • a resilient strip 21 extends obliquely downward from the base strip 15, which resilient portion has a free end remote from the base portion, fitted underneath the head of a stud 22 on the frame portion 4. As is shown in FIG. 2 the resilient portion tends to pivot the head support 13 about the knife-edge bearings in the direction of the arrow B, so that the projection 18 is urged against the head of the screw 19.
  • the positioning device 23 against the wall 16 a positioning device 23 is mounted, by means of which the magnetic head 6 is connected to the head support 13.
  • the positioning device 23 includes first and second holders 24 and 25, made of an easy-to-manufacture yet rigid material, such as die-casting zinc.
  • the first holder 24 extends over the entire height of the wall 17 of the head 6, and which is preferably glued to the wall 17.
  • the second holder 25 and the supporting portion 14 are provided with mutually co-operating adjusting means.
  • These means are constituted by adjusting pins 26 and 27 provided on the holder 25, which pins, as shown in FIG. 4, are situated in adjusting slots 28 and 29 respectively in the supporting portion 14.
  • the longitudinal axes of the respective slots 28 and 29 preferably extend perpendicularly to the long side wall of the cassette 3 so that the distance of the magnetic head from the relevant long side wall of the cassette 3 can be adjusted by moving the pins 26 and 27 in the slots 28 and 29 respectively. This is of importance to allow accurate adjustment of the distance over which the magnetic head 6 is movable into the cassette 3 through the movement of the frame portion 4.
  • the second holder 25 is furthermore provided with a bolt 30, whose head is positioned against the supporting portion 14 and whose shank is guided in a slot formed in the supporting portion 14 in such a way that this bolt does not impair the operation of the said adjusting means. After the magnetic head has been positioned by means of the adjusting means the bolt 30 is tightened, so that the second holder 25 is secured. As viewed in FIG. 2 the second holder 25 extends along the supporting portion 14, the upper part of the holder 25 being situated at a distance above the top of the supporting portion 14.
  • the upper part of the holder 25 constitutes a supporting portion 31, against which an upper mounting portion 32 of an electromechanical piezoelectric ceramic deflection element 33 is fixed.
  • the upper mounting portion 32 is situated adjacent the top edge of the piezo-electric element 33. Adjacent its bottom edge the piezo-electric element has another mounting portion 34, which is fixed on a supporting portion 35 of the first holder 24.
  • the mounting portions 34 and 32 will be referred to hereinafter as the "first" and the "second” fixing portion, respectively.
  • a rigid connection is made between the piezo-electric element and the holders 24 and 25 by gluing. This ensures that adjacent its bottom and top edges the piezo-electric element is rigidly connected to the magnetic head 6 and the head support 13, respectively.
  • the active part which is situated between the fixing portions, is situated freely and is thus movable together with the first fixing portion 34 relative to the holder 25 in a manner to be discussed hereinafter.
  • This movement is limited by portions constituting stops which are formed on the holders 24 and 25 and which are constituted by pairs of projections 36a and 37a on the holders 24 and 25 respectively, as well as by a projection 36b glued to the element 33 and a projection 37b, provided on the holder 25.
  • the projections 36a and 37a are situated one on each side of the element 33 at the level of the adjacent supporting portion 31 of the second holder 25.
  • the piezo-electric element 33 lies substantially halfway between the walls 16 and 17. When it is in a neutral rest position, the element 33 is situated straight above the said knife-edge bearings in the aforesaid plane which contains these bearings and which extends substantially parallel to said walls.
  • elastic hinges 38 and 39 are situated one on each side of the piezo-electric element 33 between the holders 24 and 25.
  • the hinges 38 and 39 are constituted by end portions of a wire spring 40, which portions are connected to the two holders 24 and 25, the diameter of said spring being approximately 0.10 to 0.15 mm and a central portion of the spring being situated in a groove 41 in the holder 25, as shown in FIG. 4.
  • the groove 41 comprises two parts which form an obtuse angle with each other, the central portion of the spring 40 having a corresponding shape. It has been found that owing to this shape the location of the pivotal axis of the elastic hinges most accurately coincides with the pivotal axis about which the magnetic head is pivotable by the piezo-electric element in a manner to be described hereinafter.
  • the magnetic head is mounted in such a way relative to the piezo-electric element 33 that the fixing portions 32 and 34 of the piezo-electric element are situated near the corners formed between the side wall 17 and the adjoining bottom and top walls 43 and 42 of the magnetic head.
  • the active portion of the piezo-electric element 33 in a direction perpendicular to the frame portion 4, has a dimension which substantially corresponds to the distance between the walls 42 and 43.
  • a substantially U-shaped cover 44 which together with the supporting portion 14 and the base portion 15 of the head support constitutes a shield which encloses the positioning device 23 and the magnetic head 6 and which protects the magnetic head and the positioning device against extraneous mechanical or electromagnetic influences.
  • the head support 13 is furthermore provided with a tape guide 45, which adjoins the supporting portion 14 and which extends towards the said long side wall of the cassette 3, and of which tape guide a portion 46 is shaped so that adjoining tape-guide limbs 47 and 48 are situated in a plane which is spaced at approximately equal distances from the walls 16 and 17 and is parallel to these walls.
  • both the pivotal axis of the knife-edge bearings and the piezo-electric element 33, the pivotal axis of the elastic hinges 38 and 39 and the tape-guide limbs 47 and 48 are situated in a plane which is situated halfway between said walls 16 and 17.
  • the holder 24 is preferably glued against the wall 17 in such a position that when the element 33 is in the restposition, the limbs 47 and 48 are accurately aligned relative to the upper and lower side of the head face 50.
  • connection plate 49 On the side which is remote from the cassette 3 the head support 13 is provided with a connection plate 49, on which the various connections of the magnetic head 6 and the piezo-electric element 33 are arranged.
  • the operation of the apparatus described in the foregoing is as follows.
  • the magnetic tape 2 in the cassette 3 is provided with recorded information by means of a magnetic recording head, which information is contained in a number of tracks on the tape.
  • a magnetic recording head which information is contained in a number of tracks on the tape.
  • azimuth-angle position is to be understood to mean the angle which the longitudinal axes of respective gaps 51 and 52 which terminate in the head face 50, form with the axis of the relevent information track, the magnetic head generally having a correct azimuth-angle position if the longitudinal axes of the air gaps extend perpendicularly to the axis of the information track these axes therefore defining an orthogonal coordinate system.
  • the output signals of the gap halves of the relevant air gap 51 or 52 are applied to a phase discriminator, which produces a control signal which is a measure of the phase difference between the said output signals and and thus of the azimuth error obtaining, which control signal is applied through a control circuit of the apparatus to the piezo-electric element 33 of the positioning device 23 in order to correct the azimuth error by positioning the magnetic head.
  • azimuth correction This is generally referred to as "azimuth correction".
  • the piezo-electric deflection element 33 comprises two layers of a piezo-electric material, which layers are polarized perpendicularly to the surface, the directions of polarisation of the two layers being opposed to one another.
  • the element 33 shown is of the so-called "bimorph" type, which means that, in addition to two electrodes which are situated on the respective outer sides of the element, and which are connected to the control circuit, a conductive electrode is arranged between the two layers.
  • the piezo-electric element 33 is rigidly connected to the second holder 25 through the second fixing portion 32. In this way the fixing portion 32 is rigidly connected to the head support.
  • the element 33 If a control voltage is applied to the element 33 through the external electrodes, which voltage is supplied by the control circuit of the apparatus, the element has the property of bending with a constant curvature along the length of the element in any given position into which the element bends. As a result of this, the first fixing portion 34 of the element will perform a pivotal movement. As the fixing portion 34 is secured to the first holder 24 and is thus rigidly connected to the magnetic head 6, the magnetic head will also be pivoted under the influence of the control voltage.
  • a line 53 tangential to the fixing portion 34 constantly extends through a point which in the neutral position of the element 33 is situated at equal distances, designated by the reference numeral 54, from the two fixing portions 32 and 34.
  • the position of a pivotal axis 55 about which the pivotal movement is effected is accurately defined by the distance 54.
  • the pivotal axis 55 extends at least substantially perpendicularly to a plane tangential to the head face 50 at the location of the termination of the air gaps 51 and 52.
  • the pivotal axis 55 coincides with the pivotal axis of the elastic hinges 38 and 39 and owing to the arrangement of the fixing portions 32 and 34 relative to the magnetic head 6 is situated at substantially equal distances from the top and bottom walls 42 and 43 of the magnetic head 6.
  • a very effective protection of the element, in order to limit the maximum permissible deflection of the piezo-electric element, is simply realised by the presence of portions constituting stops, comprising the projections 36a, 36b, 37a, and 37b. In the neutral position of the piezo-electric element these projections are spaced at small distances from each other; in the embodiment shown this distance is preferably approximately 0.05 mm.
  • the magnetic head can accurately be adjusted to its nominal position during assembly, which means that when the element 33 is in the non-energized rest position the head is adjusted so that the air gaps 51 and 52 occupy the correct perpendicular position relative to the longitudinal axis of a magnetic tape. Moreover, this permits a readjustment in a situation in which a correction of the neutral position of the element 33 is desired, for example owing to the occurrence of hysteresis effects in the element 33 and the co-operating parts of the positioning device 23.
  • the height of the magnetic head 6 relative to the frame portion 4 is determined by the various parts of the frame portion 4, which can be accurately manufactured, the head support 13 and the positioning device 23, no further height adjustment of the magnetic head relative to the frame portion 4 is then necessary.
  • a slight height variation of the magnetic head 6 relative to the frame portion 4 may occur, so that the location of the air gap 51 or 52 relative to the information track on the tape is slightly shifted, but this height variation is so small, having regard to the location of the pivotal axis 55 in the direct vicinity of the wall 17 of the magnetic head and at a level approximately halfway between the tape guide limbs 47 and 48, that in general no significant deterioration of the information signal to be reproduced occurs.
  • FIG. 6 shows an arrangement of the positioning device 23 in a second embodiment of an apparatus in accordance with the invention, which may exhibit a small displacement of the magnetic head in the direction A as a result of azimuth correction, but which exhibits substantially no height variation relative to the frame portion 4.
  • a piezo-electric deflection element 57 which substantially corresponds to the element 33 of the preceding embodiment, is situated at the underside of the magnetic head 6 between the bottom wall 43 of the magnetic head and the upper surface of the base portion 15 of the head support 13.
  • the magnetic head and the positioning device are enclosed by a shield which is constituted by the head support 13 and a cover 56.
  • the piezo-electric element 57 extends substantially parallel to the bottom wall and is secured to a first holder 59 through first fixing portion 58 by glueing or clamping.
  • Holder 59 is preferably glued to the wall 43 near its junction with the wall 17.
  • the first fixing portion 58 of the element 57 is rigidly connected to the magnetic head.
  • the element 57 is rigidly connected to the magnetic-head support 13 via a second fixing portion 60 and a second holder 61.
  • the holders 59 and 61 also constitute stops which limit the pivotal movement of the magnetic head 6.
  • an elastic hinge 62 whose pivotal axis, as in the preceding embodiment, coincides with the pivotal axis about which the first fixing portion 58 and the magnetic head 6 connected thereto are pivotable.
  • the elastic hinge 62 can be made of a plastic and be secured to the magnetic head and the head support by glueing, but it is alternatively possible to make the elastic hinge of spring steel as in the first embodiment.
  • the location of the pivotal axis about which the magnetic head 6 is pivotable by the action of the element 57 is selected so that this axis is situated near the underside of the magnetic head in a plane containing the air gaps so that the previously described advantage of the minimum height variation of the magnetic head in the case of a small displacement of the magnetic head in the direction A is obtained during pivoting, while forces acting on the magnetic head are effectively taken up by the elastic hinge 62.
  • the longitudinal axis of the element 57 extends parallel to the transport direction A, the element 57 in the present embodiment is already fairly insensitive to forces exerted on the magnetic head 6 by the magnetic tape.
  • a piezo-electric deflection element 63 is situated in the space bounded by the top wall 42 of the magnetic head 6 and that wall of the cover 56 which is parallel thereto.
  • the fixing portions 64 and 65 situated at opposite edges of the piezo-electric element 63 are fixed in U-shaped holders 66 and 67 respectively by glueing or clamping. These holders are preferably made of a ceramic material and are rigidly connected to the wall 42 and the cover 56 respectively. In this embodiment the holders 66 and 67 also constitute stops which limit the pivotal movement of the magnetic head 6 so as to protect the element 63 against overloading.
  • the pivotal axis about which the magnetic head 6 is pivotable is situated in a plane containing the air gaps 51 and 52, but in the present embodiment adjacent the top of the magnetic head, yielding similar advantages when the magnetic head is pivoted.
  • the element 63 can be adapted to withstand all the forces exerted on the magnetic head 6 by making the element 63 comparatively wide in a direction perpendicular to the tape or cassette.
  • a further advantage of the construction is that owing to the compactness of the positioning device the size of the shield around the magnetic head can be so small that the casing generally used for such a magnetic head may be employed as the shield.
  • the magnetic head 6 is provided with two magnetic cores 68 and 69 which bound air gaps 70 and 71 respectively.
  • the air gaps 70 and 71 also are divided into gap halves 70a, 70b and 71a, 71b, and the magnetic cores 68 and 69 are each divided into adjacent core portions 68a, 68b and 69a, 69b respectively.
  • the arrangement of the magnetic cores 68 and 69, as is shown in FIG. 9, is such that the magnetic cores 68 and 69 converge relative to each other in the direction of the head face of the magnetic head.
  • a space 72 is formed in the magnetic head, in which space a piezo-electric deflection element 73 is situated over at least substantially its entire length.
  • the element 73 In its neutral position the element 73 extends approximately parallel to the frame portion 4 and is disposed at least substantially symmetrically relative to the air gaps 70 and 71.
  • the element 73 is mounted on a vertical side wall 78 of the magnetic head 6 and the vertical supporting portion 14 of the head support 13 respectively by means of fixing portions 74 and 75 via holders 76 and 77 respectively.
  • the arrangement of the magnetic head 6 relative to the head support 13 is substantially insensitive to forces exerted on the magnetic head.
  • This embodiment also provides a very compact arrangement, which may be accommodated in the normally used magnetic-head casing.
  • IRH integrated recording head
  • MRH magnetic resistance head
  • control circuit of the apparatus in accordance with one of the preceding embodiments may be provided with a circuit as described in the non-prepublished Netherlands Patent Application No. 78 05802 to which U.S. patent application Ser. No. 41,021 filed May 21, 1979 corresponds (now U.S. Pat. No. 4,259,605), in order to ensure that during recording, when the positioning device 23 is inoperative, the magnetic head 6 occupies a well-defined neutral position, so that during recording the air gaps are in the correct perpendicular position relative to the longitudinal axis of the magnetic tape. Without such a circuit it is possible that in certain circumstances the element neutral position is not well-defined as a result of hysteresis effects, so that during recording the air gaps will assume an incorrect position.
  • a magnetic recording head 79 is mounted on the frame portion 4 between the erase head 5 and the magnetic head 6, which in the present embodiment is only used for reproduction.
  • Said magnetic recording head 79, in contradistinction to the magnetic reproducing head 6, is not provided with a positioning device, so that the azimuth-angle position of the head 79 remains fixed after assembly.
  • the magnetic reproducing head 6 is provided with a piezo-electric deflection element in accordance with one of the preceding embodiments. It is possible to mount the magnetic heads 6 and 79 on a common head support and to accommodate the two heads within a shield, so that a minimal space is required.
  • An advantage of this construction is that the position of the magnetic recording head 79 is not influenced by the positioning device of the magnetic reproducing head 6 and in particular the said hysteresis effects do not affect the position of the magnetic recording head 79, so that said circuit for correcting hysteresis effects is not required in the present embodiment.
  • electrostrictive deflection element instead of the piezo-electric deflection elements 33, 57, 63 and 73 described in the foregoing it is alternatively possible to employ a so-called electrostrictive deflection element.
  • This element also has a bimorph structure, i.e. it comprises two plates with an electrically conductive layer (electrode) on both sides, which plates are glued to each other.
  • these plates are made of a ferro-electric ceramic material with a high dielectric constant.
  • the outer layers should be electrically biassed.
  • the main advantage of such an electrostrictive element is the virtual absence of hysteresis, so that steps for elmininating hysteresis effects may not be necessary.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
US06/454,212 1979-09-28 1982-12-29 Magnetic head mounting mechanism for automatic azimuth control Expired - Fee Related US4451862A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL7907218A NL7907218A (nl) 1979-09-28 1979-09-28 Apparaat voor het opnemen en/of weergeven van informatie op een magneetband.
NL7907218 1979-09-28

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US06187657 Continuation 1980-09-16

Publications (1)

Publication Number Publication Date
US4451862A true US4451862A (en) 1984-05-29

Family

ID=19833934

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/454,212 Expired - Fee Related US4451862A (en) 1979-09-28 1982-12-29 Magnetic head mounting mechanism for automatic azimuth control

Country Status (9)

Country Link
US (1) US4451862A (enrdf_load_html_response)
EP (1) EP0026523B1 (enrdf_load_html_response)
JP (1) JPS5658128A (enrdf_load_html_response)
AT (1) AT372797B (enrdf_load_html_response)
AU (1) AU542598B2 (enrdf_load_html_response)
CA (1) CA1149058A (enrdf_load_html_response)
DE (1) DE3068532D1 (enrdf_load_html_response)
ES (1) ES495328A0 (enrdf_load_html_response)
NL (1) NL7907218A (enrdf_load_html_response)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5191492A (en) * 1990-03-30 1993-03-02 Archive Corporation Mechanisms for a closed loop head positioner for streaming tape drives
US20110047785A1 (en) * 2009-08-25 2011-03-03 International Business Machines Corporation Methods for fabricating magnetic transducers using post-deposition tilting
US20110109998A1 (en) * 2009-11-06 2011-05-12 International Business Machines Corporation Recording head with tilted orientation
US8351152B2 (en) 2009-08-25 2013-01-08 International Business Machines Corporation Magnetic writer structures formed using post-deposition tilting

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5814228U (ja) * 1981-07-17 1983-01-28 アイワ株式会社 再生自動アジマス調節装置
JPS58102325A (ja) * 1981-12-14 1983-06-17 Nakamichi Corp 磁気ヘツドのアジマス検出方法
JPS5950030U (ja) * 1983-03-01 1984-04-03 アイワ株式会社 テ−プレコ−ダ
JPS6040018U (ja) * 1983-08-24 1985-03-20 日本マランツ株式会社 オ−トアジマス用コントロ−ルヘツド
JPS6074212U (ja) * 1983-10-27 1985-05-24 日本マランツ株式会社 磁気ヘツド

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5317316A (en) * 1976-07-30 1978-02-17 Matsushita Electric Ind Co Ltd Posture adjusting device of magnetic head
JPS543506A (en) * 1977-06-10 1979-01-11 Sony Corp Magnetic head device
US4329723A (en) * 1979-02-16 1982-05-11 U.S. Philips Corporation Adjustable mounting for a magnetic tape head

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1221271B (de) * 1960-01-30 1966-07-21 Telefunken Patent Aus Einzel-Magnetkoepfen aufgebaute feststehende Zwei- oder Mehrspur-Magnetkopf-anordnung
US3526726A (en) * 1967-09-27 1970-09-01 Ampex Piezoelectric transducer assembly for positioning a magnetic record/reproduce head
US4188645A (en) * 1978-11-02 1980-02-12 Burroughs Corporation Piezoelectric servo for disk drive

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5317316A (en) * 1976-07-30 1978-02-17 Matsushita Electric Ind Co Ltd Posture adjusting device of magnetic head
JPS543506A (en) * 1977-06-10 1979-01-11 Sony Corp Magnetic head device
US4329723A (en) * 1979-02-16 1982-05-11 U.S. Philips Corporation Adjustable mounting for a magnetic tape head

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5191492A (en) * 1990-03-30 1993-03-02 Archive Corporation Mechanisms for a closed loop head positioner for streaming tape drives
US20110047785A1 (en) * 2009-08-25 2011-03-03 International Business Machines Corporation Methods for fabricating magnetic transducers using post-deposition tilting
US8240024B2 (en) 2009-08-25 2012-08-14 International Business Machines Corporation Methods for fabricating magnetic transducers using post-deposition tilting
US8351152B2 (en) 2009-08-25 2013-01-08 International Business Machines Corporation Magnetic writer structures formed using post-deposition tilting
US9230564B2 (en) 2009-08-25 2016-01-05 Globalfoundries Inc. Methods for fabricating magnetic transducers using post-deposition tilting
US9847099B2 (en) 2009-08-25 2017-12-19 International Business Machines Corporation Methods for fabricating magnetic writer structures using post-deposition tilting
US10614835B2 (en) 2009-08-25 2020-04-07 International Business Machines Corporation Methods for fabricating magnetic writer structures using post-deposition tilting
US20110109998A1 (en) * 2009-11-06 2011-05-12 International Business Machines Corporation Recording head with tilted orientation
US8416537B2 (en) 2009-11-06 2013-04-09 International Business Machines Corporation Recording head with tilted orientation

Also Published As

Publication number Publication date
AU542598B2 (en) 1985-02-28
JPS5658128A (en) 1981-05-21
ES8105873A1 (es) 1981-06-01
NL7907218A (nl) 1981-03-31
EP0026523B1 (en) 1984-07-11
EP0026523A1 (en) 1981-04-08
ES495328A0 (es) 1981-06-01
AU6271080A (en) 1981-04-09
AT372797B (de) 1983-11-10
DE3068532D1 (en) 1984-08-16
CA1149058A (en) 1983-06-28
JPS6211404B2 (enrdf_load_html_response) 1987-03-12
ATA478980A (de) 1983-03-15

Similar Documents

Publication Publication Date Title
JPS6135609B2 (enrdf_load_html_response)
EP0063398B1 (en) Magnetic-tape cassette apparatus and magnetic-head unit for use in conjunction with such apparatus
US4451862A (en) Magnetic head mounting mechanism for automatic azimuth control
GB1579853A (en) Automatic scan tracking
US4962438A (en) Magnetic head mounting plate with tape movement limiting surface
EP0302756B1 (en) Movable rotary head assembly
US5739984A (en) damping loop for a tape drive actuator with a servo control system
US5016132A (en) Magnetic recording and reproducing tape guide unit
JP2871851B2 (ja) 磁気テープ機械
CA2019371A1 (en) Magnetic-tape cassette
US4564157A (en) Magnetic recording tape cassette
US5038241A (en) Magnetic recording/playback apparatus having magnetic head assembly adapted to be replaced by users
US3649773A (en) Recording head adjustment mechanism
US4156258A (en) Head positioning device for multi-track tape recorders
GB2134691A (en) Tape guide assembly
JP2527765Y2 (ja) 小型テープカセット
JP3164359B2 (ja) 回転ドラム装置
JPS633000Y2 (enrdf_load_html_response)
JPH0121548B2 (enrdf_load_html_response)
JPS6235143Y2 (enrdf_load_html_response)
JP3511739B2 (ja) ヘッド素子の高さ調整装置及びこれを備える磁気テープ記録及び／又は再生装置
JPH0573859A (ja) マルチトラツクヘツドユニツト
JPH0636247A (ja) 回転ヘッド装置
JPS58177521A (ja) 磁気ヘツド
JPH05182160A (ja) 磁気ヘッドの支持装置

Legal Events

Date Code Title Description
FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
FP Lapsed due to failure to pay maintenance fee

Effective date: 19920531

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362